Gravitational Wave Observations

Aug, 18, 2018

Scientists to test land for LIGO


Mains Paper 3: Science & Technology | Awareness in the fields of IT, Space, Computers, robotics, nano-technology, bio-technology

From UPSC perspective, the following things are important:

Prelims level: LIGO

Mains level: Particulars and importance of the proposed LIGO


Testing Suitability of Indian site

  1. The Environment Ministry has allowed scientists to test the suitability of land in Maharashtra’s Hingoli district to host the India wing of the Laser Interferometer Gravitational Wave Observatory (LIGO) project.
  2. The project is piloted by the Department of Atomic Energy (DAE) and Department of Science and Technology (DST) and is expected to be ready by 2025.
  3. This is a key step to establishing the one-of-its-kind astronomical observatory.

What does it include?

  1. The project involves constructing a network of L-shaped arms, each four kilometers long, which can detect even the faintest ripples from cosmic explosions millions of light years away.
  2. The discovery of gravitational waves earned three U.S. scientists the Nobel for physics in 2017. The scientists were closely involved with LIGO.
  3. However the construction of such a large, sensitive device — there are only three of its kind in the world — requires an extremely flat surface.
  4. The LIGO-India consortium, made up of physicists from several institutes, had submitted a proposal to “prospect” 121 hectares of forest land in Dudhala village, Hingoli.
  5. For the LIGO project, it is to check if the land can be made perfectly level at a reasonable cost.
  6. The project is in the process of acquiring necessary land some of it is private and some barren forest land.

Network of detectors

  1. The LIGO project operates three gravitational-wave (GW) detectors.
  2. Two are at Hanford in the State of Washington, north-western USA, and one is at Livingston in Louisiana, south-eastern USA.
  3. The proposed LIGO-India project aims to move one Advanced LIGO detector from Hanford to India.
  4. The LIGO-India project is an international collaboration between the LIGO Laboratory and three lead institutions in the LIGO-India consortium:
  • Institute of Plasma Research, Gandhinagar
  • IUCAA, Pune
  • Raja Ramanna Centre for Advanced Technology, Indore
  1. The LIGO lab would provide the complete design and all the key detector components.
  2. Indian scientists would provide the infrastructure to install the detector and it would be operated jointly by LIGO-India and the LIGO-Lab.


Gravitational waves

  1. Gravitational waves are distortions or ‘ripples’ in the fabric of space-time caused by some of the most violent and energetic processes in the Universe.
  2. These ripples would travel at the speed of light through the Universe, carrying with them information about their cataclysmic origins, as well as invaluable clues to the nature of gravity itself.
  3. Any object with mass that accelerates (which in science means changes position at a variable rate, and includes spinning and orbiting objects) produces gravitational waves, including humans and cars and airplanes etc.
  4. But the gravitational waves made by us here on Earth are much too small to detect
  5. The strongest gravitational waves are produced by catastrophic events such as colliding black holes, the collapse of stellar cores (supernovae), coalescing neutron stars or white dwarf stars, the slightly wobbly rotation of neutron stars that are not perfect spheres, and the remnants of gravitational radiation created by the birth of the Universe itself.
  6. The LIGO is a large-scale experiment and observatory to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool.
Dec, 25, 2017

A new LIGO gravitational wave detector to be built in India by 2025


Mains Paper 3: Science & Technology | Science and Technology- developments and their applications and effects in everyday life Achievements of Indians in science & technology; indigenization of technology and developing new technology

From UPSC perspective, the following things are important:

Prelims level: Particulars of the LIGO

Mains level: Particulars and importance of the proposed LIGO


World’s third LIGO detector

  1. A new gravitational wave detector to measure ripples in the fabric of space and time is set to be built in India by 2025
  2. It will be built in collaboration with universities from across the globe
  3. Project: IndIGO

Particulars of the proposed LIGO

  1. The new Laser Interferometer Gravitational-Wave Observatory (LIGO) detector will add to the two already operational in the US
  2. The location for the new detector in India has been selected, and the acquisition has started
  3. However, the site has not been revealed yet
  4. IndIGO, the Indian Initiative in Gravitational-wave Observations, is an initiative to set up advanced experimental facilities, for a multi-institutional Indian national project in gravitational-wave astronomy
  5. The IndIGO Consortium includes
    (1) Indian Institutes of Technology (IIT),
    (2) Indian Institutes of Science Education and Research (IISER) and
    (3) Delhi University, among others


  1. A third LIGO detector will help pinpoint the origin of the gravitational waves that are detected in future
  2. The LIGO detectors discovered the first gravitational waves produced by two giant merging blackholes last year
  3. The research won a Nobel Prize in Physics this year


Gravitational Wave Observations

Oct, 17, 2017

Simply put: Now confirmed, mergers of neutron stars are factories of heavy chemical elements



Mains Paper 3: Science & Technology | Awareness in the fields of IT, Space, Computers, robotics, nano-technology, bio-technology

From UPSC perspective, the following things are important:

Prelims level: Laser Interferometer Gravitational-Wave Observatory (LIGO), European Southern Observatory (ESO), constellation Hydra, Kilonova

Mains level: Important findings in space have been one of the favorite areas of UPSC


First direct visual identification of the source of a gravitational wave

  1. European Southern Observatory (ESO) has announced the first direct, visual identification of the source of a gravitational wave
  2. Detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) on August 17
  3. This is the first time that such an event has been seen, rather than detected, and the output of numerous telescopes, terrestrial and in orbit, compared to identify a single source
  4. Radiations were detected in optical/near-infrared wavelengths as the counterpart of a gravitational wave source

Nobel Prize for LIGO scientists

  1. On October 3, LIGO founders Rainer Weiss, Barry C Barish and Kip S Thorne were awarded the Nobel Prize in Physics for detecting gravitational waves in 2015, generated by the collision of two black holes

What led to this finding?

  1. In August this year LIGO, together with the Virgo observatory in Italy, detected waves from the cataclysmic merger of two neutron stars, designated GW170817
  2. Soon after, the Fermi space telescope detected a burst of gamma rays from the same region of space, which is a signature of massive stars in collision
  3. The ESO then organized the astrophysical equivalent of a manhunt, marshaling its own resources and those of allied organizations
  4. Its Vista, VST and La Silla telescopes in Chile, along with the US DECam telescope, located the source of light near the galaxy NEC 4993 in the constellation Hydra
  5. The signal was picked up in Hawaii and over the following weeks, about 70 observatories watched the event unfold when they were on the dark side of the earth
  6. The Hubble Space Telescope tracked it, too

What do the observations tell?

  1. The observations place the electromagnetic source at 130 light years away, which matches with the distance to GW170817
  2. It confirms that when neutron stars collide into a kilonova — a body 1,000 times brighter than the average Nova — it produces a gamma-ray burst and gravitational waves
  3. This enormous exercise has joined the dots between various forms of imaging events and objects in deep space
  4. Also, ESO’s experiment has established a much more important principle — that it is now possible to correlate the findings of instruments looking into the sky in different spectra


Gravitational waves and kilonova

  1. A gravitational wave is a ripple distorting the fabric of spacetime — literally, the universe itself – created when heavy bodies accelerate rapidly
  2. A kilonova (macronova or r-process supernova) is a type of supernova that occurs when two neutron stars or a neutron star and a black hole merge in a binary system
  3. The kilonova was a phenomenon theoretically predicted 30 years ago and was expected to emit short bursts of gamma rays
  4. Gravitational waves were predicted by general relativity a century ago, and it was surmised that colliding neutron stars would emit them
  5. Both phenomena are now observationally confirmed, and a single event is identified as the source
  6. Such phenomena are believed to have generated and spewed out into the universe metals heavier than iron, including precious metals like gold, silver and platinum
Sep, 09, 2016

First LIGO lab outside U.S. may come up in Maharashtra’s Hingoli

  1. The Laser Interferometer Gravitational-wave Observatory (LIGO) project was earlier given the in-principle approval by the Union Cabinet
  2. Scientists along with industry members will be engaged in the construction of the eight km-long beam tube at ultra-high vacuum on a levelled terrain
  3. Thus, LIGO-India will bring considerable opportunities for Indian scientists in instrumentation and development
Jun, 16, 2016

Second breakthrough for LIGO detectors

  1. Context: LIGO scientists have announced of finding second pair of merging black hole
  2. Gravitational wave detectors at Livingston, Louisiana, and Hanford have detected the wave
  3. The detection of this merger required the use of sophisticated noise filtering and mathematical analyses
  4. Earlier: A gravitational wave (GW151226) detected on December 26, 2015 and scientists conclude about the emergence of two black holes
May, 06, 2016

Breakthrough Prize for gravitational waves find

  1. Context: LIGO won prize in fundamental physics for its detection of gravitational waves
  2. LIGO: Laser Interferometer Gravitational-Wave Observatory
  3. K.G. Arun of Chennai Mathematical Institute is among the contributor
  4. He joined LEGO through the INDIGO consortium in 2012
Feb, 18, 2016

Cabinet clears LIGO-India gravitational wave observatory

  1. Background: The gravitational waves were detected by the Laser Interferometer Gravitational Wave Observatory (LIGO) — a system of detectors in Washington and Louisiana
  2. Context: LIGO-India project, it is piloted by Department of Atomic Energy (DAE) and Department of Science and Technology (DST)
  3. Project cost: at least Rs. 1,200 crore
  4. Way ahead: bring considerable opportunities in cutting edge technology for Indian industry
  5. Which will be engaged in the construction of an 8-kilometre-long beam-tube at ultra-high vacuum on a levelled terrain
  6. Research institutions in LIGO-India project :
  • Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune
  • DAE organisations: Institute for Plasma Research (IPR), Gandhinagar
  • Raja Ramanna Centre for Advanced Technology (RRCAT), Indore
Feb, 15, 2016

Indian gravity wave detector 8 years away


  1. Context: Prime Minister supported idea for a US-based LIGO detector in India but such a project is at least eight years away
  2. Background: Estimated to cost around Rs. 1,200 crore project not running into environmental or State-level hurdles
  3. Relevance: India-LIGO project (INDIGO) will be a replica of the 2 LIGO detectors and many of its components have already been built and are ready to be shipped from the United States
  4. Another Project: The Indian Neutrino Observatory (INO) project — a proposed, underground observatory in Tamil Nadu cleared by the government in 2015
  5. What happened? Stalled for over a year due to protests by activist groups, concerned over its environmental impact
  6. Way ahead:  Third detector will likely improve the chances of spotting gravitational waves
Feb, 12, 2016

Gravitational wave astronomy’s finest moment

  1. Context: The detection of gravitational waves by the scientific community
  2. Indian Contribution: Inter-University for Astronomy and Astrophysics, Pune and the Raman Research Institute (RRI), Bangalore contributed in the analysis of the LIGO data
  3. Importance: The discovery would enable astrophysicists to see the universe, which is invisible to them because about 95% of the universe is known to consist of dark matter
  4. Newtonian gravity theory would be overthrown in favour of Einstein’s gravity by this discovery
Feb, 11, 2016

Learn about Gravitational waves

  1. Gravitational waves are distortions in the space-time geometry that propagate with the speed of light, analogous to ripples on the surface of a pond
  2. Current Status: There is indirect evidence for the existence of gravitational waves from the observation of binary pulsars
  3. Research: To detect gravitational waves directly
  4. The worldwide network of gravitational wave detectors had started search for these ripples in spacetime
Feb, 11, 2016

Important discovery on gravitational waves on cards

  1. Context: Indian researchers are part of the international commitment to detect gravitational waves
  2. Historical Background: Albert Einstein predicted the existence of gravitational waves in 1915
  3. Consortium: Scientists are working with IndIGO (Indian Initiative in Gravitational-wave Observations) Consortium
  4. Organisation Involved: Inter-University Centre for Astronomy and Astrophysics-Pune
  5. How? Using Laser Interferometer Gravitational-wave Observatory
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In my opinion, although the discovery of Gravitational Waves has been rewarded with the Nobel Prize in Physics in 2017, the discovery is still on a shaky footing- because it assumes the STC to be real. Actually, the real / imaginary issue is being discussed for 100 years, with no globally accepted conclusion. In fact, as a common teacher of physics (teacher of HSC physics) I have raised a conceptual difficulty in a European review journal in April 2017. Americans and Europeans are planning the new generation of detectors (See Physics Today, October 2018) but I have raised the same issue in two comments on that article, title: Future gravitational wave detectors aim to probe early universe. Our national leaders have to consider economy because Americans and Europeans also are considering economy.